Hi Carvel,

?

I did use a very good micrometer to check the diameter in a few spots along its length, I did remember I used it to set up the mill spindle and it measured evenly with that first test by and large , I think I was chasing a bit on the lathe spindle due to dirt in the taper …. It wasn’t great !

?

What I did not do on the mill spindle was to spin it for run out at the end of the bar from memory so that needs a go over :)

?

So spoiler the lathe is fixed now and set up !

?

What I had to do was take off the motor, Access the head stock bolts and grub screws and have at it …?

It was miles out! The grub screws audibly clicked when the tension was released, It took around 10 small adjustments-checking with the bar and dti each time..

?

I got the left to right or in and out depending to within 3 microns at the end of the test bar , Well happy with that, The vertical plane is not perfect around 4 times that but I decided not to shim anything just yet-set up the tail stock and get to testing what I have.

?

The conclusion after taking a cut along a 10mm bar approximately 75mm long (with several spring passes) gave an error of 5 microns but interestingly not a taper but a very slight wave so the bed wear is influencing the cut very slightly! But the accuracy now is very much ok and manageable if maximum accuracy is needed.

?

I personally would use tail support as often as possible so I would be able to get slightly better results again, All in I think I’m set once the mill motor is returned to be re-fitted !

?

Cheers Rick